there is the united states of america. there is not a black america and a white america and latino america and an asian america, but there is the united states of america. >> from the first time he took to the kconvention speech as th keynoter in 2004, there has been no doubt that barack obama can step into the spotlight and dazzle. four years later in denver, the optics match the excitement for the presidential campaign with greek columns surrounding him in front of a crowd of more than 75,000, and the democratic nominee delivered an electric speech. >> out of work, tough luck, you are on your own. no health care? the market will fix it. you're on your own. born into poverty? pull yourself up by your own boot straps, because even if you don't have boot, you are on your own. well, it is time for them to own their failure. it is time for us to change america, and that's why i'm running for president of the united states. >> this week in tampa, the republicans argue that barack obama is a great talker who doesn't deliver. it